Jump to main content
Jump to site search


Interactions of Hg(II) with oligonucleotides having thymine-thymine mispairs. Optimization of an impedimetric Hg(II) sensor.

Abstract

The present work describes the effect of number of thymine-thymine mispairs in single strand DNA probes on Hg(II) interactions and further to develop a highly sensitive DNA based impedimetric sensor for Hg(II) detection. To achieve this goal, the influence of number of T-T mispairs on the signal response prompted by DNA-Hg(II) binding interactions were examined on three designed DNA probes: 5’-OH-(CH2)6-S-S-(CH2)6-AGTCCACACGTTCCTTACGC-3’, 5’-OH-(CH2)6-S-S-(CH2)6-AGTCCACATTTTCCTTTTGC-3’ 5’-OH-(CH2)6-S-S-(CH2)6-AGTCCATTTTTTCCTTTTTT-3’ having 2T-T, 4T-T and 6T-T mispairs with identical length, respectively. This study revealed that the number of T-T mispairs plays a critical role in maximizing the signal intensity of DNA-Hg(II) binding interactions. Based on these results, DNA comprising maximum number of T-T mispairs was further utilized for construction of the Hg(II) sensor, which exhibited the linear correlation between the change in charge transfer resistance (∆RCT) and the concentration of Hg(II) over the range of 1.0×10-5 M to 1.0×10-10 M with lower detection limit of 3.2×10-11 M. The selectivity was tested against 12 different metal ions including Hg(II). The ∆RCT response from Hg(II) is 3 times higher than the nearest competitor Pb(II) and approximately 10 times than other ions. The potential application of such robust and label-free DNA sensor was demonstrated by analyzing environmental samples collected from Lake Ontario.

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 09 Feb 2017, accepted on 13 Apr 2017 and first published on 19 Apr 2017


Article type: Paper
DOI: 10.1039/C7AN00238F
Citation: Analyst, 2017, Accepted Manuscript
  •   Request permissions

    Interactions of Hg(II) with oligonucleotides having thymine-thymine mispairs. Optimization of an impedimetric Hg(II) sensor.

    A. Kamal, Z. She, R. Sharma and H. Kraatz, Analyst, 2017, Accepted Manuscript , DOI: 10.1039/C7AN00238F

Search articles by author